Refers to property insurance that insures against loss to covered property from all causes except those that are specifically excluded. This method of identifying covered causes of loss in a property policy has traditionally been referred to as "all risks" coverage. Many industry practitioners continue to use the term "all risks" to describe this approach to defining covered causes of loss in a property insurance policy. However, it is no longer used in insurance policies because of concern that the word "all" suggests coverage that is broader than it actually is. Because of this concern, some industry practitioners have begun to use the term "open perils" or "special perils" instead of "all risks."
Definition provided by the International Risk Management Institute (IRMI) Glossary of Insurance.